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kingfamous
04-30-2011, 8:58 PM
Im building my first AR and had a question on barrels. Im looking at the yankee hill 16" and they offer 1:7 and 1:9 twists. I will mostly be plinking steel and paper targets with this using the rem. umc from walmart. 55gr I think. Which barrel should I be using?

dieselpower
04-30-2011, 8:58 PM
1:9

RawImpact
04-30-2011, 9:00 PM
you should use the search function

MacDime
04-30-2011, 9:01 PM
THESE (http://www.gmriflebarrel.com/productdetail.aspx?id=GM-M5) are very good for the price.

Josh3239
04-30-2011, 9:01 PM
1:7 offers more flexibility IMO. Unless your building a retro I see no reason to go slower than a 1:7 or a 1:8.

kingfamous
04-30-2011, 9:07 PM
will the 1:7 shoot the 55 gr ok, or are they just for the heaver bullets??

Josh3239
04-30-2011, 9:08 PM
55gr leaves my 1:7 perfectly fine. They shoot better than I can.

dieselpower
04-30-2011, 9:13 PM
^I see no reason to over spin and waste power and accuracy simply because you may at some point use a few hundred rounds of an ammo you don't normally shoot.

Thats sorta stupid if you think about it. You wouldn't make that decision in other areas, why do you do that with AR15s?

analogy,
TV A has the best picture with store bought commercial DVDs, TV B has a better picture with custom DVDs you will rarely if ever get...why would you buy TV B?

Car A gets the best gas mileage with 87, and 88. 89 not so much. You never get 89 due to cost. Car B gets better gas mileage with 89 and 88. 87 not so good. Why in the freaking hell would you get Car B?

I will tell you why you get the WORSE of the two...cuz then all the really cool guys will let you hang out with them... 1:7 is a bad choice for a guy who just wants to shoot the common 40gr 55gr and 62gr ammo... If your favorite maker doesn't offer a 1:9...fine settle for the second best choice of a 1:7.

1:8 would be the better of both.

FatalKitty
04-30-2011, 9:20 PM
I chose 1:9 because it seamed to be the best bet - 62gr is widely availiable... and it'll shoot the 55gr just dandy. If I ever wanted to shoot something a little heavier... then it'll do that too :)

DigitalAmmunition
04-30-2011, 9:24 PM
I chose 1:9 because it seamed to be the best bet - 62gr is widely availiable... and it'll shoot the 55gr just dandy. If I ever wanted to shoot something a little heavier... then it'll do that too :)

That's how I feel. Ultimately training ammo tends to be 55gr cheap stuff, and the SHTF ammo tends to be the heavier nicer bullets. Price always plays its role. If there's a good deal on the heavier bullets, then even the better.

dieselpower
04-30-2011, 9:28 PM
^ yes its a no brainier. 55gr = 1:9. If you are shooting MK262 or even MK318, yeah I would think about looking for 1:8 or 1:7.

1:9 can shoot both of those just as well as a 1:7 can shoot 40gr and 55gr.

1:9 is best for under 62
1:8 is best for anything around 62 up to 77
1:7 is best for over 62

over 1:9 is used to tumble a projectile.

Veggie
04-30-2011, 9:50 PM
Who makes a good 1:9 14.5 5.56 barrel?

dieselpower
04-30-2011, 10:27 PM
Who makes a good 1:9 14.5 5.56 barrel?

Armalite (http://www.armalite.com/Catitem.aspx?Category=bce7fa68-373e-4afc-b00e-63fe2c75d131)

http://www.armalite.com/ItemForm.aspx?item=B15A2C&Category=a5c527d6-017c-40c2-80f2-59e99534f863

Veggie
04-30-2011, 10:31 PM
Armalite (http://www.armalite.com/Catitem.aspx?Category=bce7fa68-373e-4afc-b00e-63fe2c75d131)

http://www.armalite.com/ItemForm.aspx?item=B15A2C&Category=a5c527d6-017c-40c2-80f2-59e99534f863

Forgot to say Mid-Length also they don't make a 14.5.

dieselpower
04-30-2011, 10:40 PM
Forgot to say Mid-Length also they don't make a 14.5.

Thats very new. BM makes one and they very well could have gone back to 4140 or 4150CMV. checking now....NOPE...

Can I ask why you want a 14.5" mid gas?

Veggie
04-30-2011, 10:47 PM
Thats very new. BM makes one and they very well could have gone back to 4140 or 4150CMV. checking now.

Yea I am most likely going to be buying a DD 1:7 simply because there is no real other option. Other then buying a 16 and having it cut down. And I am not sure I want to go through the trouble or pay for it.

dieselpower
04-30-2011, 10:58 PM
Forgot to say Mid-Length also they don't make a 14.5.

wait. I am getting confused.

Armalite does make a 14.5... I own it, thats what I shoot. a 14.5" postban HBAR with a Brake.

so you want a 14.5 barrel with a 9.8" gas system (mid gas). Thats the same as a 14.5" barrel with a 7.8" gas system. (carbine gas). The 2" less only drops the pressure by 3,000...thats nothing. The benefit of a mid gas comes at 18" where you gain velocity and drop pressure.

Look at AR15Barrels.com last chart here, (http://www.ar15barrels.com/prod/operation.shtml) last on page.

VytamenC Tactical
04-30-2011, 11:01 PM
yankee hill makes a good barrel go with a 1:9 twist that will be fine for a 55gr bullet. if you want to shoot heavier gr bullets go with a 1;7

Veggie
04-30-2011, 11:04 PM
wait. I am getting confused.

Armalite does make a 14.5... I own it, thats what I shoot. a 14.5" postban HBAR with a Brake.

so you want a 14.5 barrel with a 9.8" gas system (mid gas). Thats the same as a 14.5" barrel with a 7.8" gas system. (carbine gas). The 2" less only drops the pressure by 3,000...thats nothing. The benefit of a mid gas comes at 18" where you gain velocity and drop pressure.

Look at AR15Barrels.com last chart here, (http://www.ar15barrels.com/prod/operation.shtml) last on page.

Maybe but it is what I want right now.

Just saw you asking why I wanted Mid Length gas. Mainly because i want to use the FSB and I want a longer hand guard for a more comfortable grip.

dieselpower
05-01-2011, 7:48 AM
Maybe but it is what I want right now.

Just saw you asking why I wanted Mid Length gas. Mainly because i want to use the FSB and I want a longer hand guard for a more comfortable grip.

If you can't get a BCM, and don't want to wait you could build yourself a mid length Dissy. Low-pro carbine gas system, hidden under mid length handguards with the slightly longer sight system that brings to the picture.

I have been thinking about a rifle gas carbine length dissy build myself. I may see if I like the way it feel by mounting a fake A2 FSB and building a rifle handguard carbine dissy first.

Veggie
05-01-2011, 10:59 AM
If you can't get a BCM, and don't want to wait you could build yourself a mid length Dissy. Low-pro carbine gas system, hidden under mid length handguards with the slightly longer sight system that brings to the picture.

I have been thinking about a rifle gas carbine length dissy build myself. I may see if I like the way it feel by mounting a fake A2 FSB and building a rifle handguard carbine dissy first.

sounds awfully expensive in the long run. i will consider it and look into it.

dieselpower
05-01-2011, 11:53 AM
sounds awfully expensive in the long run. i will consider it and look into it.

It is...sometimes its best to wait for a supplier to have what you want...LOL

as soon as BCM gets its act together will a new barrel supplier, they will have more stock.

MarioS
05-01-2011, 5:13 PM
55gr leaves my 1:7 perfectly fine. They shoot better than I can.

Same here.

OP, I've never gone long range with my 1:7 shooting 55gr., which is where I hear it can start to create problems, but it's way more accurate than I am for plinking and shooting paper. I like it because I can turn around and shoot the heavier defense loads as well. If you find a good deal on a 1:9 though, I'd go for it, it's best for 55gr. from what I understand.